With enhanced capabilities of mobile terminals, mobile subscribers may enjoy richer mobile services. On the other hand, mobile subscribers are disrupted by illegal information, junk mails, mobile phone viruses, and porn content. Subscribers hope to eliminate such illegal and disruptive information. In turn, mobile operators hope to defend their networks against mobile phone viruses and junk mails and provide subscribers with high quality services, thus increasing profits. To meet these requirements, the Open Mobile Alliance sets up a categorization-based content screening (CBCS) working group, aiming to provide a method for protecting subscribers from accessing improper contents.
Currently, contents are represented by metadata.
For example, ID3 tags are a technology widely used in media players. The ID3 tag of an MP3 file includes such information as singer name, music name, year, and music style. Except the Style (Genre) attribute, there are no categorization related contents in the ID3 tags.
In another example, MPEG-7 is a standard for the metadata of audio contents or video contents. The categorization information in the MPEG-7 includes style, topic, purpose, language, categorization, parent guide type, and topic preview.
In a specific implementation, the preceding MPEG-7 may be described through a media description scheme (MDS). In the MDS, a classification DS is used to describe the categorization information of the contents.
During the implementation of the present disclosure, the following problems were discovered: There may be multiple producers of categorization information (for example, a CBCS categorization component and a content provider that supports the CBCS categorization component) and multiple consumers of categorization information (for example, a CBCS content screening component and a client that supports the CBCS metadata format) in the CBCS. However, the classification DS of the MPEG-7 in the conventional art supports only the description scheme (for example, Motion Picture Association (MPA) and Internet Content Rating Association (ICRA)), categorization type (for example, PG-13 and PG), country, language, and style. Thus, the consumers and producers of the categorization information cannot verify the trust relationship of the categorization component by using a content screening component and perform the screening operation only after it is determined that the categorization component is trustworthy.